Plum Jam

This jam was made with a mixture of ripe and semi-ripe plums- because plums from the garden don't all ripen at the same time! This produces a slightly tart but beautiful jam. If you prefer a sweeter jam, increase the amount of sugar.

The key is to weigh the steamed plums after you have strained out the stones and skin and add just over half this weight in sugar.  Semi-ripe plums have higher levels of pectin, meaning a dash of lemon juice is enough to help the jam set - no need for gelatine.

I bought 3 x 550ml jars at KMart - perfect for the 2.2kg of plums I started with.

Sterilising the jars

Wash the jars in soapy water. Rinse thoroughly, then place the jars, opening down, in the oven at 180C for at least 20 mins. Place the lids in a pot of boiling water and leave there until you need them.  You want to time your sterilisation of the jars so that they are still hot when you put the jam in them.

INGREDIENTS 

2.2 kg of plums

670g of caster sugar

Juice of 1/2 a lemon

Note: adjust according to weight of lums you have

METHOD 

Wash the plums and remove any damaged ones.

Place the plums in a large pot and heat over a medium heat, stirring often with a wooden spoon until the plums break down into a thick liquid. Depending on the plums you use you may need to add a little water to help the plums stew. I didn't in this case.

Weigh a large container then strain the plums through a collander into the container. This will remove the stones and skin. Use the wooden spoon to push through as much pulp as you can. Weigh the stewed plums, then measure out just over half the same weight of sugar.  Return the stewed plums to the pot, add the sugar and lemon juice, them bring to a simmer, stirring often.

Place two small plates in the freezer. You will use these to check whether the jam will set.

As the mixture thickens, start to test the setting point of the jam after about 12 mins of simmering. You don't want the mixture darkening too much or the sugar will burn.

To test, remove a plate from the freezer. Spoon a small amount (less than 1 tsp) of jam onto the plate. Allow the jam to cool completely, then with your finger push from one side and make a dent in the jam. When the gap in the jam you make doesn't fill back in and the jam wrinkles slightly, the jam is ready to move to jars.

Turn off the heat. In a separate large pot, add boiling water up to about half the level of your jars. Working quickly, take the hot jars from the oven and place on a heatproof surface, eg a wooden chopping board. Funnel the jam equally into the jars, leaving 1 to 1.5 cm space at the top. Place the jars in the hot water in the other pan. The hot water should be 3/4 of the way up the jars now but not spilling into the jam. Then remove the lids from the hot water they are in and loosely fit them to the jars. Bring the water to a boil, then carefully screw the lids tight. This seals the jam jars and allows you to keep the jam for many months. 

However, once opened, use within 2 weeks or so.